Die for making elbow pipe



Aug 25, 1953 J. PETRESKY, JR 2,549,642

DIE FOR MAKING ELBOW PIPE l INVENTOR ATTORNEYS Aug. 25, 1953 J. PE1-mism, .JR

DIE FoR MAKING ELBOW PIPE Filed oct. 12, 1951 2 Sheets-Sheet 2 l a 12; f :f

ZE l l L 1 12S I 4 f; Q 12 Z2 i-i N EW@ E INVENTOR ATTORNEYS Patented Aug. 25, 1953 DIE FOR MAKING ELBOW PIPE" John Petresky, Jr., Patton, Pa., assignor to Patton Clay Manufacturing Co., Inc., Patton, Pa., a corporation of Pennsylvania Application October 12, 1951, Serial No. 251,061

(Cl. :Z-39) 5 Claims.

My invention relates to dies and formers of the type widely used in the forming and extrusion of clay pipe, such as that used in sewer installations, and more particularly relates to dies and formers of the general type shown in U. S. Patent #2,282,282' used to manufacture pipe of plastic material, said pipe having an enlarged bell portion at one end.

The principal object of my invention is to provide a die having a lower bell portion in which the pipe bell is molded, which bell portion is opened in a novel manner to permit more eicient production of elbow pipe sections by cutting down the amount of manual labor involved in opening and closing of the bell portion.

Another primary object of my invention is to provide a novel former member adapted when engaged with the die to lock the bell portion of the die closed, and adapted when disengaged from the die to release the bell portion and permit it to swing away from the die so .that the pipe may be bent around to assume an elbow shape, the purpose of the opening of the bell portion of the die being to permit the pipe to be bent nearer to the extrusion neck of the die as the pipe extrudes therefrom so that a right-angle elbow may be formed in a minimum overall length of pipe.

Broadly speaking, the mere opening of the bell portion of the die to permit sharp bending of the pipe is not novel. Hinged bell openings are shown in U. S. Patents 738,913; 2,554,011, and 2,502,247, wherein the whole bell is opened after the pipe bell has been molded. However, in these prior art patents, since the whole bell opens, it is necessary to provide latch means for holding the bell portions closed. The latch means not only unnecessarily complicates the assembly, but wastes the time of the operator who must, each time, latch and release it. In addition, it is deemed unnecessary to open the whole bell when only a segment thereof need be opened to render the die fully useful in the manufacture of elbow pipe. It is therefore an important object of my invention to provide a die wherein only a segment of the bell is opened so that the remaining portion of the bell may be formed as a strong integral part of the die. the opening segment being pivotally fixed to the die on a hinge transversely disposed with respect to the axis of theA die so that upward pressure against the segment when in closed position will hold it closed, and so that release of such upward pressure will permit the segment to pivot4 open under the influence of gravity. The opening of only a segment of the die bell has the advantages of not only providing a stronger structure since a large portion of the bell is integral with theV die, but also of providing a die which whenr opened projects outwardlyv only in one direction instead of having several relatively large members projecting outwardly in several directions to take up space unnecessarily and to become a hazard to the operator.. This initial opening of the segment is, moreover, assisted during the downward receding of the former member by the downward motion of that portion of the newly molded pipe bell which is in contact with the segment in its closed position.

This die lends itself to extrusion operations wherein the pipe is manually bent into elbow form, such manual bending being consistent practice in the clay pipe industry. There is, however, no reason why such a segmented bell opening can not be used in dies having mechanism for automaticallyA bending the pipe into elbow form. In any case, it might be useful to provide bias means on the segment to force it into fully opened position as the former member retracts away from the die bell.

Other objects and advantages of my invention will become apparent during the following discussion of one practical embodiment of my invention shown in the accompanying drawings wherein:

Figure 1 is a sectional elevational of Vmy die and former showing in dotted lines the bell segment in open position.

Fig. 2 is a bottom view of thedie with the former removed.

Fig. 3 is a sectional elevation of the die extruding a right-angle elbow, the bell segment being shown in openposition.

Fig. 4 is an elevation of the former member with the outer flange thereof` in section.

Referring to the drawings, the device comprises an outer die I having an upper conical portion la; reducing downwardly to an extrusion neck lIb below which is a lower bell portion Ic. At the upper end of the die I is a flange Id having mounting holes therethrough, this flange being useful in attaching the die to a pressurized clay reservoir (not shown). On the side of the die near the necked down portion lb is a boss le for the purpose hereinafter discussed. The die has a core member 2 which may be made in separable sections as illustrated by dashed lines in Fig. 1, the core member being of .rather conventional design. In addition, the die may be provided with an annular wear insert If at the extrusion neck Ib.

A former member 3 is provided to engage with the bell portion le of the die, the 4latter having a chamfered lower edge lg adapted to fit into a complementary recess 3g in the former member 3, Fig. 4. A raised core portion 3a is provided in the center of the former 3 to abut against the core 2 of the die'when the former is closed against the die as shown in Fig. l. The former member 3 forms with the lower bell Ic of the die -a mold which shapes the bell vportion BP ofthe clay pipe P during the initial Vstep in the manu- 3 facture of the pipe at which time the' former and die are in engagement as shown in Fig. 1.

As shown in Figs. 1 and 2 a segment ls of the lower bell ic is openable along a line X and along lines Y. This segment ls is attached to a hinge 4, the hinge being in turn Xed to the boss' le on the die. This structure perni-its thesegment ls to be pivoted inwardly to emplete the annular bell ic, or to be pivoted outwardly as shown in Fig. 3 to open one side of the bell Ic.

In operation, the die l and former 3 are closed so that the cores 2 and 3a. abut. The clay is then pressed down through the extrusion neck Ib and into the pipe bell mol-ding portion. Pis soon as the pipe bell BP has been formed., the former member 3 is retracted so that the chamfers Ig are released from the recess 3g. The body of the pipe P begins to be extruded past the wear insert if and at this point the segment Is drops downwardly and outwardly away from the pipe bell BP. segment is can either be manually' pivoted to the position shown in Fig. 3', or chanioal means may be provided to cause the segment is to automatic-ally assume sueh position. The is usually provided with a restrictor 5 just above the neel; to, this r'estriotor' il causing less oiay to through the extrusion neck to on the" side adjacent the segment is, thereby causing the pipe P to have a' natural tendency to bend as' it is extruded. Manual or mechanical support may be provided beneath the pipe P as it extrudes. to help' the pipe maintain the desired elbow anglewithout breakage.

When the elbow is' completed and separated from the die, the segment is' is againl returned to closed position in whioh position it is tightly .seoured by' the'A closing oi the former member tl'iereagainst. The die is then ready to beginthe znol'ding. and extrusion of. another pipe elbow.

i. do not my' invention. to the exact form shown in the drawing forobv'iously ohanges may be within the'l scope of the' following claims.

l claim:

l. in Xtrusionf andi molding device' for manuelbotv pipe having a; pipe bell at one end, comprising a hollow die. said diie having an extrusion portion terminating in arr enlarged annular beit molding' portion and said niol'dling portion having a segment of its annularl periphery openable an'dhinged? to the die, a core extending through' s'aid die, and a former member adapted to engage with the molding portion to maintain the segment Closed position to complete the periphery of said molding portion and toprovide a mold to forni the pipe bell, said segment gravitationally hinging` away from said molding portion when said former' member is disengaged therefrom.

An extrusion andv molding device for ina-nufaeturing elbow pipe having a pipe bell at one end, oomprisngv a hollow die, said die having a vertical extrusion portion terminating below in an enlarged annular bell molding portion and said molding portion having a segment ofV its annular periphery openable and horizontally hinged to the a corev extending through said extrusion portionr and terminating above said molding portion;y an`d a former member having an' upwardly disposed core portion, adapted to engage" upwardly' with the molding portion and core to maintain the segment in closed position to complete the periphery of said molding portion and to provide amold to form the pipe bell, saidsegment being released to drop by gravity uiacturing elbow pipe having a pipe bell at one end, comprising a hollow die, said die having a vertical extrusion portion terminating below in an enlarged annular bell molding portion and said molding .portion having a segment of its annular periphery openable; a core extending through said extrusion portion and terminating above said molding portion; a hinge fixed to the outside of the die and having its pivot horizontally disposed, said hinge connecting the segment and thev die; and a former member having an annular reeess to receive the outer periphery of the bell portion and having a core portion, said former member when engaged upwardly with the bell portion maintaining the segment in Closed position to complete the periphery of said molding portions: and said core portion abutting said core to lprovide a moldto form the pipe bell, and said segment being released to drop by gravity away from said' molding portion when said former is lowered out of engagement therewith.

4. An extrusion and molding devise for manufacturing elbow pipe having a pipe bell at one end, comprising a hollow die, said die having an extrusion portion terminating in an enlarged annular bell molding portion and said molding portion' having a segment of its annu-lar periphery ope-liable; a core extending through saidextrusion portion; a hinge disposed transversely of the artis oi the die and eonneoting the segment and the die; and a former member having an annular reeess to receive the outer periph-ery of the moldportion and having a core portion,y saidy former member when engaged with the molding portion maintaining the segment in closed position to complete the periphery of said molding portion core portion abutting said core to provide a mold to form the pipe bell.

5. An extrusion and molding devise for manufacturing from material in a plastic state elbow pipe having a pipe bell at one end, comprising a hollow die; said die having extrusion portion terminating in an enlarged annular bell molding portion and saidmolding portion having a segment of its: annular periphery openable; a sore extending through said extrusionportion; a hinge disposed transversely of the axis of the' die and connecting the segment andthe die; means for restricting the flow of material on one side of the extrusion portion to give the pipe a natural tendency to bendin the direction` oi the segand a former member having an annular recess? to'reoeive the outer periphery of the molding portion and having a ooreportion', said former member when: engaged with the molding portion main-taining the segment in closed position to complete the periphery of said molding portion, and said core portionv abutting sai-d core to provide a mold to form the pipe bell, said segment being openable'when saidA former member is disengaged from said molding portionv to permit the pipe to be bent adjacent said extrusion portion` as the material extru'des therefrom.

JOHN PETRESKY, Je'.

References Cited in' the fileof this patent UNITED STATES PATENTS 

